The present invention is directed to an attachment device or channel nut assembly base including a base member or channel nut, a cap member and a flexural member, with the base member made up of a non-circular head, a threaded opening extending through the head and at least one first anti-rotation surface. The cap member has at least one through opening and at least one second anti-rotation surface for engagement with the first anti-rotation surface, so that the two surfaces cannot rotate relative to one another but only rotate as a unit.
An installation system is disclosed in CH-PS 597 450 including an attachment member in the form of an attachment rail comprising a hollow section of rectangular cross-section with at least one recess in a long direction of the rail in the form of a slot-like opening for insertion of one or more attachment devices. The slot-like opening is limited in width by the free ends of a pair of legs.
The attachment rail has locking grooves serving to axially secure the attachment device. The attachment device comprises a base member with a non-circular head, a intermediate member and an clamping member, wherein the attachment member is able to clamp or tighten the base member and the cap member against one another, for securing such an attachment device to an attachment rail located on a ceiling so that its slot-like opening faces downwardly. The base member of the attachment device is placed into the slot-like opening and turned through 90.degree., whereby the non-circular head rests inside the attachment rail at the inner side of the two legs.
This known device demonstrates that the attachment device can be fixed to the attachment rail merely by turning the base member without the possibility of loosening it. When securing this known attachment device, the base member must be turned at least partially, so that the non-circular head of the base member rests at the inner side of the legs.
Depending on the manner in which it is used, it is necessary to align the attachment device relative to an attachment member by displacing the device with respect to the attachment member shaped as a fastening rail. The known attachment devices can no longer be displaced after they have been finally clamped and tightened against the fastening rail, since a portion of the base member projects into locking grooves on the fastening rail.